I normally buy netbook type computers - 7" to 11" - because I spend most of my time hitchhiking around the world and when I'm at home I plug into external monitor, drive, keyboard, mouse, etc.
I want the very cheapest. It's liable to get lost, broken, or stolen on my travels. I'm willing to accept inferior CPU and graphics and less RAM and storage. These I regard as natural limits.
But I hate artificial limits.
Back when netbooks were super popular just before iPads came out, Microsoft offered cheap Windows licenses to OEMs if they put artificial limits such as 32-bit only, maximum RAM 4gb, etc.
I also hate soldered-in RAM, non-replaceable batteries, etc.
I also regard proprietary hardware with no free drivers for Linux to be an artificial limit.
So which are the cheapest laptops which are small like netbooks but support 64-bit OSes and have upgradeable RAM etc?
(MacBooks and Ultrabooks are several times the price of netbook class laptops. Intermediate priced laptops in my part of the world are generally full size - 14" to 17".)